#region License, Terms and Conditions
//
// Jayrock - JSON and JSON-RPC for Microsoft .NET Framework and Mono
// Written by Atif Aziz (atif.aziz@skybow.com)
// Copyright (c) 2005 Atif Aziz. All rights reserved.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the Free
// Software Foundation; either version 2.1 of the License, or (at your option)
// any later version.
//
// This library is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
// details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this library; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
//
#endregion

namespace Studio.Foundation.Json.Core.Conversion.Converters
{
    #region Imports

    using System;
    using System.ComponentModel;
    using System.Diagnostics;
    using CustomTypeDescriptor = Conversion.CustomTypeDescriptor;
    using System.Collections.Generic;
    using System.Reflection;

    #endregion
    
    public sealed class ComponentImporter : ImporterBase
    {
        private readonly PropertyDescriptorCollection _properties; // TODO: Review thread-safety of PropertyDescriptorCollection

        public ComponentImporter(Type type) :
            this(type, null) {}

        public ComponentImporter(Type type, ICustomTypeDescriptor typeDescriptor) :
            base(type)
        {
            if (typeDescriptor == null)
                typeDescriptor = new CustomTypeDescriptor(type);
            
            _properties = typeDescriptor.GetProperties();
        }

        protected override object ImportFromObject(ImportContext context, JsonReader reader)
        {
            Debug.Assert(context != null);
            Debug.Assert(reader != null);

            reader.Read();


            if (null != OutputType.GetConstructor(Type.EmptyTypes))
            {
                object o = Activator.CreateInstance(OutputType);

                while (reader.TokenClass != JsonTokenClass.EndObject)
                {
                    string memberName = reader.ReadMember();

                    PropertyDescriptor property = _properties.Find(memberName, true);

                    if (property != null && !property.IsReadOnly)
                        property.SetValue(o, context.Import(property.PropertyType, reader));
                    else
                        reader.Skip();
                }
                return ReadReturning(reader, o);
            }
            else
            {
                // object o = Activator.CreateInstance(OutputType);
                Dictionary<string, object> properties = new Dictionary<string, object>();
                while (reader.TokenClass != JsonTokenClass.EndObject)
                {
                    string memberName = reader.ReadMember();

                    PropertyDescriptor property = _properties.Find(memberName, true);

                    if (property != null)
                        properties.Add(memberName, context.Import(property.PropertyType, reader));
                    else
                        reader.Skip();
                }

                ConstructorInfo[] list = OutputType.GetConstructors();
                object o = null;
                foreach (ConstructorInfo con in list)
                {
                    ParameterInfo[] paramList = con.GetParameters();
                    object[] parameters = new object[paramList.Length];
                    bool isFound = true;
                    for(int i = 0; i < paramList.Length; i++)
                    {
                        ParameterInfo paramInfo = paramList[i];
                        if (false == properties.ContainsKey(paramInfo.Name)) 
                        {
                            isFound = false;
                            break;
                        }
                        Type actual = properties[paramInfo.Name].GetType();
                        Type expect = paramInfo.ParameterType;
                        if(actual != expect && false == expect.IsAssignableFrom(actual))
                        {
                            isFound = false;
                            break;
                        }
                        parameters[i] = properties[paramInfo.Name];
                    }

                    if (isFound)
                    {
                        try
                        {
                            o = Activator.CreateInstance(OutputType, parameters);
                        }
                        catch (Exception ex)
                        { 
                            o = null;
                        }
                        if (null != o)
                            break;
                    }

                    if (null == o)
                        throw new Exception("Can not construct type: " + OutputType.FullName);

                    foreach (KeyValuePair<string, object> pair in properties)
                    {
                        PropertyDescriptor property = _properties.Find(pair.Key, true);
                        if(false == property.IsReadOnly)
                            property.SetValue(o, pair.Value);
                    }
                }

                return ReadReturning(reader, o);
            }
        }
    }
}
